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Finding the Fourth Proportional to 661.28, 992.34 and 387.92

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Solution

The fourth proportional to 661.28, 992.34 and 387.92 is: 582.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.28 : 992.34 = 387.92 : x
  2. Step 2: Convert to fraction form
    661.28/992.34 = 387.92/x
  3. Step 3: Cross multiply
    661.28x = 992.34 × 387.92
  4. Step 4: Simplify right side
    661.28x = 384,948.53
  5. Step 5: Solve for x
    x = 384,948.53/661.28
  6. Step 6: Final answer
    x = 582.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.